2 * Copyright 2002-2005, Instant802 Networks, Inc.
3 * Copyright 2005-2006, Devicescape Software, Inc.
4 * Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
5 * Copyright 2007 Johannes Berg <johannes@sipsolutions.net>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
11 * utilities for mac80211
14 #include <net/mac80211.h>
15 #include <linux/netdevice.h>
16 #include <linux/types.h>
17 #include <linux/slab.h>
18 #include <linux/skbuff.h>
19 #include <linux/etherdevice.h>
20 #include <linux/if_arp.h>
21 #include <linux/wireless.h>
22 #include <linux/bitmap.h>
23 #include <net/net_namespace.h>
24 #include <net/cfg80211.h>
25 #include <net/rtnetlink.h>
27 #include "ieee80211_i.h"
32 /* privid for wiphys to determine whether they belong to us or not */
33 void *mac80211_wiphy_privid = &mac80211_wiphy_privid;
35 /* See IEEE 802.1H for LLC/SNAP encapsulation/decapsulation */
36 /* Ethernet-II snap header (RFC1042 for most EtherTypes) */
37 const unsigned char rfc1042_header[] __aligned(2) =
38 { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00 };
40 /* Bridge-Tunnel header (for EtherTypes ETH_P_AARP and ETH_P_IPX) */
41 const unsigned char bridge_tunnel_header[] __aligned(2) =
42 { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0xf8 };
45 u8 *ieee80211_get_bssid(struct ieee80211_hdr *hdr, size_t len,
46 enum ieee80211_if_types type)
50 /* drop ACK/CTS frames and incorrect hdr len (ctrl) */
54 fc = le16_to_cpu(hdr->frame_control);
56 switch (fc & IEEE80211_FCTL_FTYPE) {
57 case IEEE80211_FTYPE_DATA:
58 if (len < 24) /* drop incorrect hdr len (data) */
60 switch (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) {
61 case IEEE80211_FCTL_TODS:
63 case (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS):
65 case IEEE80211_FCTL_FROMDS:
71 case IEEE80211_FTYPE_MGMT:
72 if (len < 24) /* drop incorrect hdr len (mgmt) */
75 case IEEE80211_FTYPE_CTL:
76 if ((fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_PSPOLL)
78 else if ((fc & IEEE80211_FCTL_STYPE) ==
79 IEEE80211_STYPE_BACK_REQ) {
81 case IEEE80211_IF_TYPE_STA:
83 case IEEE80211_IF_TYPE_AP:
84 case IEEE80211_IF_TYPE_VLAN:
97 int ieee80211_get_hdrlen(u16 fc)
101 switch (fc & IEEE80211_FCTL_FTYPE) {
102 case IEEE80211_FTYPE_DATA:
103 if ((fc & IEEE80211_FCTL_FROMDS) && (fc & IEEE80211_FCTL_TODS))
104 hdrlen = 30; /* Addr4 */
106 * The QoS Control field is two bytes and its presence is
107 * indicated by the IEEE80211_STYPE_QOS_DATA bit. Add 2 to
108 * hdrlen if that bit is set.
109 * This works by masking out the bit and shifting it to
110 * bit position 1 so the result has the value 0 or 2.
112 hdrlen += (fc & IEEE80211_STYPE_QOS_DATA)
113 >> (ilog2(IEEE80211_STYPE_QOS_DATA)-1);
115 case IEEE80211_FTYPE_CTL:
117 * ACK and CTS are 10 bytes, all others 16. To see how
118 * to get this condition consider
119 * subtype mask: 0b0000000011110000 (0x00F0)
120 * ACK subtype: 0b0000000011010000 (0x00D0)
121 * CTS subtype: 0b0000000011000000 (0x00C0)
122 * bits that matter: ^^^ (0x00E0)
123 * value of those: 0b0000000011000000 (0x00C0)
125 if ((fc & 0xE0) == 0xC0)
134 EXPORT_SYMBOL(ieee80211_get_hdrlen);
136 unsigned int ieee80211_hdrlen(__le16 fc)
138 unsigned int hdrlen = 24;
140 if (ieee80211_is_data(fc)) {
141 if (ieee80211_has_a4(fc))
143 if (ieee80211_is_data_qos(fc))
144 hdrlen += IEEE80211_QOS_CTL_LEN;
148 if (ieee80211_is_ctl(fc)) {
150 * ACK and CTS are 10 bytes, all others 16. To see how
151 * to get this condition consider
152 * subtype mask: 0b0000000011110000 (0x00F0)
153 * ACK subtype: 0b0000000011010000 (0x00D0)
154 * CTS subtype: 0b0000000011000000 (0x00C0)
155 * bits that matter: ^^^ (0x00E0)
156 * value of those: 0b0000000011000000 (0x00C0)
158 if ((fc & cpu_to_le16(0x00E0)) == cpu_to_le16(0x00C0))
166 EXPORT_SYMBOL(ieee80211_hdrlen);
168 unsigned int ieee80211_get_hdrlen_from_skb(const struct sk_buff *skb)
170 const struct ieee80211_hdr *hdr = (const struct ieee80211_hdr *)skb->data;
173 if (unlikely(skb->len < 10))
175 hdrlen = ieee80211_hdrlen(hdr->frame_control);
176 if (unlikely(hdrlen > skb->len))
180 EXPORT_SYMBOL(ieee80211_get_hdrlen_from_skb);
182 int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr)
184 int ae = meshhdr->flags & IEEE80211S_FLAGS_AE;
200 void ieee80211_tx_set_protected(struct ieee80211_tx_data *tx)
202 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data;
204 hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
205 if (tx->extra_frag) {
206 struct ieee80211_hdr *fhdr;
208 for (i = 0; i < tx->num_extra_frag; i++) {
209 fhdr = (struct ieee80211_hdr *)
210 tx->extra_frag[i]->data;
211 fhdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
216 int ieee80211_frame_duration(struct ieee80211_local *local, size_t len,
217 int rate, int erp, int short_preamble)
221 /* calculate duration (in microseconds, rounded up to next higher
222 * integer if it includes a fractional microsecond) to send frame of
223 * len bytes (does not include FCS) at the given rate. Duration will
226 * rate is in 100 kbps, so divident is multiplied by 10 in the
227 * DIV_ROUND_UP() operations.
230 if (local->hw.conf.channel->band == IEEE80211_BAND_5GHZ || erp) {
234 * N_DBPS = DATARATE x 4
235 * N_SYM = Ceiling((16+8xLENGTH+6) / N_DBPS)
236 * (16 = SIGNAL time, 6 = tail bits)
237 * TXTIME = T_PREAMBLE + T_SIGNAL + T_SYM x N_SYM + Signal Ext
240 * 802.11a - 17.5.2: aSIFSTime = 16 usec
241 * 802.11g - 19.8.4: aSIFSTime = 10 usec +
242 * signal ext = 6 usec
244 dur = 16; /* SIFS + signal ext */
245 dur += 16; /* 17.3.2.3: T_PREAMBLE = 16 usec */
246 dur += 4; /* 17.3.2.3: T_SIGNAL = 4 usec */
247 dur += 4 * DIV_ROUND_UP((16 + 8 * (len + 4) + 6) * 10,
248 4 * rate); /* T_SYM x N_SYM */
251 * 802.11b or 802.11g with 802.11b compatibility:
252 * 18.3.4: TXTIME = PreambleLength + PLCPHeaderTime +
253 * Ceiling(((LENGTH+PBCC)x8)/DATARATE). PBCC=0.
255 * 802.11 (DS): 15.3.3, 802.11b: 18.3.4
256 * aSIFSTime = 10 usec
257 * aPreambleLength = 144 usec or 72 usec with short preamble
258 * aPLCPHeaderLength = 48 usec or 24 usec with short preamble
260 dur = 10; /* aSIFSTime = 10 usec */
261 dur += short_preamble ? (72 + 24) : (144 + 48);
263 dur += DIV_ROUND_UP(8 * (len + 4) * 10, rate);
269 /* Exported duration function for driver use */
270 __le16 ieee80211_generic_frame_duration(struct ieee80211_hw *hw,
271 struct ieee80211_vif *vif,
273 struct ieee80211_rate *rate)
275 struct ieee80211_local *local = hw_to_local(hw);
276 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
281 if (sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
282 erp = rate->flags & IEEE80211_RATE_ERP_G;
284 dur = ieee80211_frame_duration(local, frame_len, rate->bitrate, erp,
285 sdata->bss_conf.use_short_preamble);
287 return cpu_to_le16(dur);
289 EXPORT_SYMBOL(ieee80211_generic_frame_duration);
291 __le16 ieee80211_rts_duration(struct ieee80211_hw *hw,
292 struct ieee80211_vif *vif, size_t frame_len,
293 const struct ieee80211_tx_info *frame_txctl)
295 struct ieee80211_local *local = hw_to_local(hw);
296 struct ieee80211_rate *rate;
297 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
301 struct ieee80211_supported_band *sband;
303 sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
305 short_preamble = sdata->bss_conf.use_short_preamble;
307 rate = &sband->bitrates[frame_txctl->control.rts_cts_rate_idx];
310 if (sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
311 erp = rate->flags & IEEE80211_RATE_ERP_G;
314 dur = ieee80211_frame_duration(local, 10, rate->bitrate,
315 erp, short_preamble);
316 /* Data frame duration */
317 dur += ieee80211_frame_duration(local, frame_len, rate->bitrate,
318 erp, short_preamble);
320 dur += ieee80211_frame_duration(local, 10, rate->bitrate,
321 erp, short_preamble);
323 return cpu_to_le16(dur);
325 EXPORT_SYMBOL(ieee80211_rts_duration);
327 __le16 ieee80211_ctstoself_duration(struct ieee80211_hw *hw,
328 struct ieee80211_vif *vif,
330 const struct ieee80211_tx_info *frame_txctl)
332 struct ieee80211_local *local = hw_to_local(hw);
333 struct ieee80211_rate *rate;
334 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
338 struct ieee80211_supported_band *sband;
340 sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
342 short_preamble = sdata->bss_conf.use_short_preamble;
344 rate = &sband->bitrates[frame_txctl->control.rts_cts_rate_idx];
346 if (sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
347 erp = rate->flags & IEEE80211_RATE_ERP_G;
349 /* Data frame duration */
350 dur = ieee80211_frame_duration(local, frame_len, rate->bitrate,
351 erp, short_preamble);
352 if (!(frame_txctl->flags & IEEE80211_TX_CTL_NO_ACK)) {
354 dur += ieee80211_frame_duration(local, 10, rate->bitrate,
355 erp, short_preamble);
358 return cpu_to_le16(dur);
360 EXPORT_SYMBOL(ieee80211_ctstoself_duration);
362 void ieee80211_wake_queue(struct ieee80211_hw *hw, int queue)
364 struct ieee80211_local *local = hw_to_local(hw);
366 if (test_bit(queue, local->queues_pending)) {
367 tasklet_schedule(&local->tx_pending_tasklet);
369 if (ieee80211_is_multiqueue(local)) {
370 netif_wake_subqueue(local->mdev, queue);
373 netif_wake_queue(local->mdev);
377 EXPORT_SYMBOL(ieee80211_wake_queue);
379 void ieee80211_stop_queue(struct ieee80211_hw *hw, int queue)
381 struct ieee80211_local *local = hw_to_local(hw);
383 if (ieee80211_is_multiqueue(local)) {
384 netif_stop_subqueue(local->mdev, queue);
387 netif_stop_queue(local->mdev);
390 EXPORT_SYMBOL(ieee80211_stop_queue);
392 void ieee80211_stop_queues(struct ieee80211_hw *hw)
396 for (i = 0; i < ieee80211_num_queues(hw); i++)
397 ieee80211_stop_queue(hw, i);
399 EXPORT_SYMBOL(ieee80211_stop_queues);
401 void ieee80211_wake_queues(struct ieee80211_hw *hw)
405 for (i = 0; i < hw->queues + hw->ampdu_queues; i++)
406 ieee80211_wake_queue(hw, i);
408 EXPORT_SYMBOL(ieee80211_wake_queues);
410 void ieee80211_iterate_active_interfaces(
411 struct ieee80211_hw *hw,
412 void (*iterator)(void *data, u8 *mac,
413 struct ieee80211_vif *vif),
416 struct ieee80211_local *local = hw_to_local(hw);
417 struct ieee80211_sub_if_data *sdata;
421 list_for_each_entry(sdata, &local->interfaces, list) {
422 switch (sdata->vif.type) {
423 case IEEE80211_IF_TYPE_INVALID:
424 case IEEE80211_IF_TYPE_MNTR:
425 case IEEE80211_IF_TYPE_VLAN:
427 case IEEE80211_IF_TYPE_AP:
428 case IEEE80211_IF_TYPE_STA:
429 case IEEE80211_IF_TYPE_IBSS:
430 case IEEE80211_IF_TYPE_WDS:
431 case IEEE80211_IF_TYPE_MESH_POINT:
434 if (sdata->dev == local->mdev)
436 if (netif_running(sdata->dev))
437 iterator(data, sdata->dev->dev_addr,
443 EXPORT_SYMBOL_GPL(ieee80211_iterate_active_interfaces);
445 void ieee80211_iterate_active_interfaces_atomic(
446 struct ieee80211_hw *hw,
447 void (*iterator)(void *data, u8 *mac,
448 struct ieee80211_vif *vif),
451 struct ieee80211_local *local = hw_to_local(hw);
452 struct ieee80211_sub_if_data *sdata;
456 list_for_each_entry_rcu(sdata, &local->interfaces, list) {
457 switch (sdata->vif.type) {
458 case IEEE80211_IF_TYPE_INVALID:
459 case IEEE80211_IF_TYPE_MNTR:
460 case IEEE80211_IF_TYPE_VLAN:
462 case IEEE80211_IF_TYPE_AP:
463 case IEEE80211_IF_TYPE_STA:
464 case IEEE80211_IF_TYPE_IBSS:
465 case IEEE80211_IF_TYPE_WDS:
466 case IEEE80211_IF_TYPE_MESH_POINT:
469 if (sdata->dev == local->mdev)
471 if (netif_running(sdata->dev))
472 iterator(data, sdata->dev->dev_addr,
478 EXPORT_SYMBOL_GPL(ieee80211_iterate_active_interfaces_atomic);